Prostate carcinomas are being studied in germfree and conventional Lobund Wistar rats. Three transplantable tumor lines uniformly produce metastatic tumors which are being used for investigations on etiology, metastasis, pathogenesis, and prevention and treatment of disease. The tumor cells are being propagated in vitro as cell monolayers which reconstitute adenocarcinomas when inoculated subcutaneously into Lobund Wistar rats. BIBLIOGRAPHIC REFERENCES: Pollard, M. and P. H. Luckert. Chemotherapy of metastatic prostatic adenocarcinoma in germfree rats. Cancer Treatment Reports, 60:619-621, 1976. Celesk, R. A. and M. Pollard. Ultrastructural cytology of prostate carcinoma cells from Wistar rats. Investigative Urology, 14:95-99, 1976.